Agent mobility is the ability of an agent to migrate from one location to another. So far, there ... more Agent mobility is the ability of an agent to migrate from one location to another. So far, there are several difficulties with agent s' migration due to the lack of interoperability among agent middleware that is distributed over the net. In this paper, an abstract software migration architecture is presented, which is the first step towards full agent middleware interoperability.
2014 IEEE/WIC/ACM International Joint Conferences on Web Intelligence (WI) and Intelligent Agent Technologies (IAT), 2014
A contemporary governance challenge for governments concerns the biogas domain: what incentives a... more A contemporary governance challenge for governments concerns the biogas domain: what incentives and policies can lead to a viable biogas economy? To support addressing this challenge, a prototype of a simulator is constructed in which horizontal governance is applied in a multi-stakeholder context. This paper reports on the modelling and knowledge acquisition that led to the development of that prototype. Rather than (re)inventing tooling, three available agent-based modelling approaches are combined: the MAIA meta-model, OperA and GENIUS; with AgentScape as the agent-based middleware for the realisation of the simulator. The resulting simulator has been validated by biogas experts from Alliander (NL-based energy network company), leading to confirmation that our combined approach was useful for the analysis of this multi-stakeholder domain.
Agent platforms designed for Internet-scale, open networks need scalable and secure location serv... more Agent platforms designed for Internet-scale, open networks need scalable and secure location services for agents and services. The location service based on the Fonkey public key distribution infrastructure presented in this paper has been designed and implemented for this purpose. It is scalable in the total number of published identifier-contact address pairs, the number of updates/changes, and the number of agent platforms publishing and requesting contact addresses. This system also supports a signing mechanism to authenticate the publisher of an identifier-contact address pair. Experimental results show that the current implementation based on the Bunshin/Free Pastry overlay network exhibits good scaling behavior. 2 Background The most widely used location service on the Internet today is Domain Name System (DNS) [2]. DNS defines a hierarchical name space used to map computer host names and other resources to IP addresses. DNS is a distributed database that allows for scalable operation by distributing the hierarchical name space over many servers, each responsible for a specific part of the name space. DNSSEC [3] is a security extension for DNS that cryptographically ensures DNS data is not forged or altered. The DNSSEC extensions provide data integrity and authentication through the use of digital signatures. The Lightweight Directory Access Protocol (LDAP) [4] is a directory service that can also be used as a location service. The LDAP protocol is designed to provide access to directories supporting the X.500 models. The directory access protocol provides both read and update access. Update access requires secure authentication. LDAP organizes data in a hierarchy using the Distinguished Name (DN). Like DNS, LDAP allows distribution over multiple servers based on the hierarchical name. Van Steen et al. [5] present a location service for mobile objects in a worldwide system named Globe. The mobile object location service strictly separates an object's name from the location on which it resides. This is done by binding an object's name to a location-independent object handle, which, in turn, is mapped to the location where the object resides. The location service is organized as a distributed search tree. To achieve scalability of the hierarchical location service, where potentially high-level nodes may become a bottleneck, location information is distributed such that the load is evenly balanced, while at the same time exploiting locality [6]. Name and location service NLS extends the Globe location service by using prefixes to aggregate location information and using a two-layer architecture with fat-trees at the global layer [7]. Locating mobile agents in worldwide distributed systems is also specifically addressed in a number of research papers. Di Stefano and Santoro [8] propose a naming scheme and location protocol with intended general validity for mobile agents able to effectively meet all the typical requirements of mobile agent environments and, thus, straightforward to integrate into different platforms. Functionality for authentication of hosts publishing location updates and information integrity is not, however, considered in their system. Roth and Peters [9] propose a global tracking service for mobile agents, designed to scale to the Internet, and to be secure. Their location information load sharing approach is similar to the Globe location service, but does not presuppose coherent mobile agent migration patterns to achieve scalability. The protocols presented by Roth and Peters have a number of advantageous security properties, in particular, malicious location updates by unauthorized hosts are prevented. A scalable hash-based mobile agent location mechanism is proposed by Kastidou et al. [10]. A mobile agent tracking mechanism based on hashing is presented, and dynamic rehashing is supported to allow the system to adapt to variable workloads. The research reported in this paper has defined design goals similar to the global tracking system presented in [9], namely a scalable and secure location service for mobile agents. However, the location service system presented in this paper includes data integrity verification.
Enforcing integrity of agent migration paths by distribution of trust. Int
Agent mobility is the ability of an agent to migrate from one location to another across a networ... more Agent mobility is the ability of an agent to migrate from one location to another across a network. Though conceptually rela-tively straightforward, in practice security of mobile agents is a chal-lenge: from transport layer security to preservation of integrity in open environments. This paper discusses the security issues involved and proposes protocols for secure agent migration. AgentScape, an agent platform for mobile agents, is used to illustrate the feasibility of the implementation of these protocols.
A Framework for Developing Agent-Based Distributed Applications
Abstract—The development of large-scale distributed multiagent systems in open dynamic environmen... more Abstract—The development of large-scale distributed multiagent systems in open dynamic environments is a challenge. System behavior is often not predictable and can only be evaluated by execution. This paper proposes a framework to support design and development of such systems: a framework in which both simulation and emulation play an important role. A distributed agent platform (AgentScape) is used to illustrate the potential of the framework. Keywords-multi-agent systems, agent-based simulation, emulation, development, distributed systems I.
Abstract—The development of agent applications in large-scale, distributed, open environments is ... more Abstract—The development of agent applications in large-scale, distributed, open environments is a challenge. This paper proposes a framework to support development and deployment of distributed agent applications. The trajectory from design to real-world deployment starts with simulation and ends with emulation. The framework is illustrated with AgentScape, a distributed agent platform. Keywords-multi-agent systems, agent-based simulation, em-ulation, development I.
Agent mobility is the ability of an agent to migrate from one location to another across a networ... more Agent mobility is the ability of an agent to migrate from one location to another across a network. Though conceptually relatively straightforward, in practice security of mobile agents is a challenge: from transport layer security to preservation of integrity in open environments. This paper discusses the security issues involved and proposes protocols for secure agent migration. AgentScape, an agent platform for mobile agents, is used to illustrate the feasibility of the implementation of these protocols. Keywords:
Integrity of mobile agents in open environments in which no guarantees can be provided on the int... more Integrity of mobile agents in open environments in which no guarantees can be provided on the integrity of the hosts on which they run, is an open challenge. This paper presents a method with which tampering can be detected. This method is based on the notion of distributed trust; trust distributed over the hosts involved.
Mobile data offloading: an agent-based modelling study on the effectiveness of Wi-Fi offloading
To reduce the load on cellular networks, offloading to Wi-Fi has long been discussed as a technol... more To reduce the load on cellular networks, offloading to Wi-Fi has long been discussed as a technological solution. Despite advances in scheduling algorithms and incentive schemes, most mobile operators do not actively promote Wi-Fi offloading and most Wi-Fi usage is limited to stationary in-home contexts of use. This study assesses the proportion of users on the street that can be offloaded to Wi-Fi access points, taking into account different city topologies, speed of movement and technical characteristics of Wi-Fi access points. We show that the proportion of users on the street that can be offloaded to Wi-Fi heavily depends on their speed of moving around, the reach of access points and the delay in logging on to access points. However, even when using standard configurations for access points, base stations and smartphones, half the outdoor users can be offloaded to Wi-Fi. These results are consistent for any type of realistic topology of roads in the city. Based on the results, ...
Multi Agent Systems (MAS) provide a useful paradigm for accessing distributed resources in an aut... more Multi Agent Systems (MAS) provide a useful paradigm for accessing distributed resources in an autonomic and self-directed manner. Resources, such as web services, are in-creasingly becoming available in large distributed environ-ments. Currently, numerous multi agent systems are avail-able. However, for the multi agent paradigm to become a genuine mainstream success certain key features need to be addressed: the foremost being security. While security has been a focus of the MAS community, configuring and man-aging such multi agent systems typically remains non-trivial. Well defined and easily configurable security policies address this issue. A security architecture that is both flexible and featureful is prerequisite for a MAS. A novel security policy enforcement system for multi agent middleware systems is introduced. The system facilitates a set of good default configurations but also allows extensive scope for users to develop customised policies to suit their individual needs....
This chapter presents the currently not established and identifies design requirements for new sy... more This chapter presents the currently not established and identifies design requirements for new systems to address this challenge and provide directions for possible improvement. As a result, this chapter introduces the concept of SamenMarkt®, a participatory system in which multi-agent system technology enables distributed price negotiation, distribution and communication between producers, retailers and consumers.
The development of agent applications in largescale, distributed, open environments is a challeng... more The development of agent applications in largescale, distributed, open environments is a challenge. This paper proposes a framework to support development and deployment of distributed agent applications. The trajectory from design to real-world deployment starts with simulation and ends with emulation. The framework is illustrated with AgentScape, a distributed agent platform. Keywords-multi-agent systems, agent-based simulation, emulation, development
Automated support for management of complex distributed object-oriented systems is a challenge: s... more Automated support for management of complex distributed object-oriented systems is a challenge: selfmanagement is the goal. A self-management system needs to reason about the behaviour of the distributed entities in a system, and act when necessary. The knowledge needed is multi-leveled: different levels of concepts and rules need to be represented. This paper explores the requirements that hold for representing this knowledge in self-managed distributed object-oriented systems, and explores the potential of Semantic Web technology in this context.
Integrity of mobile agents in open environments in which no guarantees can be provided on the int... more Integrity of mobile agents in open environments in which no guarantees can be provided on the integrity of the hosts on which they run, is an open challenge. This paper presents a method with which tampering can be detected. This method is based on the notion of distributed trust; trust distributed over the hosts involved.
The Design of a High-Integrity Disk Management Subsystem
... In the early stages of the LD-project, Reind van de Riet, Hans van Staveren, and Gregory Shar... more ... In the early stages of the LD-project, Reind van de Riet, Hans van Staveren, and Gregory Sharp also worked on the project. ... I have spent the most time: Chris & Maartje Niekel, Jaap Kreijkamp, Gerard Kok, Mirna Bognar, Jerry den Hartog, Paulien de Wind, Jeroen Ketema, Gerco ...
In this paper we present an agent-based approach to facilitate context-based adaptations using co... more In this paper we present an agent-based approach to facilitate context-based adaptations using context information of a group of users. To minimize the effort to collect all relevant information of the current collaboration situation, and the amount of data to be kept, we propose a decentralized, agent-based approach that keeps track of the contextualized state.
... of Computer Science, The Netherlands rjtimmer@cs.vu.nl Frances Brazier Vrije Universiteit Ams... more ... of Computer Science, The Netherlands rjtimmer@cs.vu.nl Frances Brazier Vrije Universiteit Amsterdam, Dept. of Computer Science, The Netherlands frances@cs.vu.nl Julian Padget University of Bath Dept. ... Springer, Berlin, 2006. [8] S. Phelps, M. Marcinkiewicz, and S. Parsons. ...
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Papers by Michel Oey